1. Field of the Invention
The present invention relates to a cylinder housing for an auxiliary lock. More particularly, the present invention relates to a cylinder housing for a cylinder of an auxiliary lock. The present invention also relates to an auxiliary lock with such a cylinder housing.
2. Description of the Related Art
U.S. Pat. No. 5,906,125 discloses an auxiliary lock comprising a ring having a central opening and a first flange received in a door bore-hole, a cylinder housing having a shoulder abutting the ring and a hollow protrusion extending into the central opening of the ring, the hollow protrusion having a flat outer wall, a trim enclosing over the cylinder housing, and a cylinder having a rear end received within the hollow protrusion of the cylinder housing and a shoulder abutting the trim, the flat outer wall of the protrusion being intimately interposed between the ring and the rear end of the cylinder. The cylinder housing and the trim are retained in a fixed relationship with respect to the door. The ring further includes a second flange, and a free end of the trim adjacent to the shoulder of the cylinder housing is situated between the shoulder of the cylinder housing and the second flange of the ring. The trim, when rotated by an external force, will rotate with respect to the ring but not drive the cylinder housing to rotate, therefore the auxiliary lock will not be damaged.
However, an intruder can still destroy the auxiliary lock by breaking the coupling section between the elements, such as the coupling section between the ring and the trim. The ring would no longer protect the cylinder after the elements are separated from one another after destruction. Further, the auxiliary lock of this type is complicated in structure and, thus, has a higher cost due to troublesome assembling.